273results about How to "Improve linear range" patented technology

A current sensor and current transformer for monitoring electrical current is provided with a magnetic core having a mixture of magnetic materials to provide a low cost design in a compact configuration with an expanded dynamic range. The mixed material core can be fabricated either from stamped laminations or from coil stock and may include an air gap for activating a magnetic flux sensor. Multiple core configurations, including Figure-O, Figure-C, and Figure-8, having mixed material construction are disclosed and offer advantages over non-mixed material cores where dynamic range and frequency response characteristics are a consideration.

The invention discloses a method for preparing a nanometer Co-Fe prussian-blue complex-carbon nano tube composite hydrogen peroxide sensor, which comprises the following steps of: a, preparing Co-Fe prussian-blue complex nano particles; b, performing surface pretreatment on a glassy carbon electrode; c, mixing the Co-Fe prussian-blue complex nano particles and an acidized multi-walled carbon nano tube ultrasonically for 30 to 60 minutes; and d, dropping and coating the ultrasonically-mixed solution in the step c on the glassy carbon electrode, and drying by using an infrared lamp to obtain the novel hydrogen peroxide sensor. In the nanometer Co-Fe prussian-blue complex-carbon nano tube composite hydrogen peroxide sensor prepared by the method, the linear range response to H2O2 is between 1 micrometer and 1.1 millimeters, the detection limit is 0.25 micrometer, and the sensitivity is 255 micro A mM<-1>cm<-2>, so the method is high in sensitivity and low in detection limit.

A sensor, in particular a Hall sensor, comprising a sensor element (1; 10) which outputs a sensor signal (SS) containing an interference signal (STS). An evaluation device (6; 20) is connected to the sensor element and contains a subtractor (2; 21) which subtracts the interference signal from the sensor signal. The sensor contains a filter device (3), which filters out the interference signal from the sensor signal. The sensor and a related method enable compensation of the interference signal.

A directional loudspeaker unit for reproducing mid-range audio frequencies, comprising a cone loudspeaker and, disposed forwardly of the surface of the cone of the loudspeaker, a phase plug and a horn, wherein the phase plug and preferably also the horn are arranged co-axially on the axis of the cone, and wherein the phase plug has a central aperture. Preferably the horn has a diffraction slot defined by lateral walls which converge from the entrance (throat) of the horn.

The present invention is directed to a method for the determination of a target nucleic acid using a special control nucleic acid, a method for the amplification of a partial sequence of said target nucleic acid using primers, a special control and a kit containing said control. The sequence of these control nucleic acids are at least in part parallel-complementary to the sequence of the target nucleic. These controls have similar properties as the target nucleic acid in hybridization and amplification methods, but can be well differentiated from the target nucleic acid by their different sequence.

The invention discloses a transcription factor detection method based on DNA-Ag nanoclusters molecular beacons and exonuclease III cycle signal amplification. The novel nanomaterial DNA-Ag nanoclusters molecular beacon is applied as a fluorescent probe to transcription factor detection for the first time. Also, based on the characteristic that fluorescence adjustment of DNA-Ag nanoclusters molecular beacons is carried out by an enzyme cleavable DNA fragment, exonuclease III is added to participate in signal transformation and also participate in enhancement of the detection signal. The transcription factor detection method provided by the invention has the advantages of no label, high selectivity, low cost and high sensitivity, and can realize high throughput detection of transcription factors in biological samples.

The invention relates to the field of biological and medical detection technologies, specifically discloses a chemiluminescence immunodetection kit for the ovarian cancer tumor marker HE4 and also discloses a method of using the chemiluminescence immunodetection kit for the ovarian cancer tumor marker HE4 for detecting the ovarian cancer tumor marker HE4. The chemiluminescence immunodetection kit comprises a microplate coated by 9F3 antibodies, 10 E1 antibodies labeled by alkaline phosphatase, an analysis buffer solution, substrate operating fluid, a luminescent substrate, washing liquid and a quality control. The chemiluminescence immunodetection kit for the ovarian cancer tumor marker HE4 provided in the invention has a linear range of 0.5 ng/ml to 1200 ng/ml and a detection limit of 0.2 ng/ml, can be used for clinical auxiliary diagnosis, curative effect observation and prognosis of ovarian cancers and has important significance to treatment and prevention of ovarian cancer tumors.

The invention relates to super-resolution dual-axis differential confocal measurement method and device for division focal spot detection, which belong to the technical field of optical precision measurement. By utilizing the characteristic that the transversal deflection of a detector makes the axial response curve of the dual-axis confocal microscopy generate displacement, adopting the transversal differential detection method of a division focal spot to receive and process a measuring optical beam in the dual-axis confocal microscopy, and combining a super-resolution pupil filtering technology, the method and the device achieve the purposes of enhancing the system resolution, extending the working distance, enhancing the anti-jamming capability and improving the linear range. The invention can be used for the precision measurement of microelectronics, materials, industry precision detection, biomedical field and the like.

The invention discloses a method for simultaneously detecting multiple mycotoxins in milk. The method comprises the following steps: (1) extracting the mycotoxins from milk to obtain a crude mycotoxin extract; (2) purifying and concentrating the crude mycotoxin extract; (3) carrying out gradient eluting on the concentrated mycotoxins on a chromatographic column through a mobile phase and collecting eluate; and (4) qualitatively and quantitatively detecting the collected eluate by a mass spectrometer. An efficient, sensitive and stable method is created in the invention for simultaneously detecting aflatoxin M1, ochratoxin A, zearalenone and alpha-zearalenol in milk. The linearity, sensitivity, recovery, accuracy and reproducibility of the detection method disclosed by the invention are verified in fresh milk, liquid milk and milk powder, and as shown in the verification results, the detection method disclosed by the invention is good in linear range, high in sensitivity, good in credibility and strong in stability.

The invention relates to a biosensor, particularly relates to a preparation method and catalytic application of a Nafion/horseradish peroxidase/tricobalt tetraoxide-graphene/ionic liquid carbon paste electrode (Nafion/HRP/Co3O4-GR/CILE) and belongs to the technical field of electrochemical analysis and detection. According to the preparation method of the Nafion/HRP/Co3O4-GR/CILE, an ionic liquid carbon paste electrode is used as a substrate electrode, and by virtue of the specific advantages of a Co3O4-GR nano composite material of large surface area and good biocompatibility, HRP is adsorbed on the surface of the material; and furthermore, the material is fixed by a Nafion film to prepare the Nafion/HRP/Co3O4-GR/CILE. HRP in the modified electrode keeps a natural structure and biological activity. Research on electrochemical properties of the modified electrode shows that the modified electrode has good electrochemical catalysis capability on trichloroacetic acid (TCA), and can be used for effectively detecting TCA, and the detection limit is 0.33mmol/L. The preparation method and the catalytic application, provided by the invention, do not cause environmental pollution; the modified electrode has good stability, repeatability and sensitivity, and the preparation process is simple, low in cost and easy to operate, so that the modified electrode has wide social benefits.

A method and apparatus for controlling temperature stability of an inductor by using a magnetically coupled metallic object is disclosed in which a metallic object is magnetically coupled to the inductor by a magnetic field emanating therefrom. In one embodiment, the apparatus is tailored for use in a proximity probe of a machine monitoring system and includes the metallic object magnetically coupled to a sensing coil for controlling a resistance versus temperature profile including compensating for a proximity effect resistance of the coil.

The invention belongs to the technical field of optical precise measurement and relates to a super-resolution double-shaft differential confocal measuring method and a super-resolution double-shaft differential confocal measuring device. In the method and the device, pupil filtering technology is fused in a double-shaft confocal measuring structure, and a differential treatment method is used for receiving a measured light beam and carrying out treatment, thereby achieving the aims of improving resolution, expanding working distance, improving anti-interference capability and improving linear range. The invention can be used for precise measurement in such fields as micro-electronics, materials, industrial precise detection, biomedicine, etc.

The invention relates to a preparation method and application of a multilevel micro-meter cubic zinc stannate composite material based photoelectrochemical sensor to cardiac troponin I and belongs tothe field of photoelectrochemical sensors. Polypyrrole/ nitrogen subtracted graphite phase carbon nitride is taken as a template for synthesis of a multilevel structural Zn2SnO4 cube; nitrogen and sulfur doped graphene quantum dot N,S-GQDs is used for sensitizing Zn2SnO4 to improve its visible light absorption; the process of in-situ growth of CdS nanoparticles is carried out to obtain a multilevel micro-meter cubic zinc stannate composite material Zn2SnO4/N,S-GQDs/Cds with photoelectric activity improved greatly; cardiac troponin I antibodies, bovine serum albumin and cardiac troponin I antigens are assembled to the composite material Zn2SnO4/N,S-GQDs by means of the layer by layer self-assembly; thus, according to the excellent photoelectric activity of Zn2SnO4/N,S-GQDs and binding of specificity of cardiac troponin I antigens and cardiac troponin I antibodies, ultra-sensitive detection to cardiac troponin I is achieved, which has a great significance in analysis and detection of cardiac troponin I.

The invention provides a background absorption correction method for CODcr measurement. The background absorption correction method comprises the following steps of carrying out pretreatment, digestion and cooling of a sample, respectively detecting sample absorbance values at wavelengths of 440+/-20nm and 600+/-20nm, calculating an amount of absorbance variation caused by background absorption according to an absorbance balance formula, deducing characteristic absorbance values at wavelengths of 440+/-20nm and 600+/-20nm respectively according to a correction formula of absorbance at a wavelength of 440nm and a correction formula of absorbance at a wavelength of 600nm, and deducing a chemical oxygen demand (COD) value of the sample according to the characteristic absorbance values. The background absorption correction method for CODcr measurement can correct CODcr measurement interference caused by background absorption, effectively improve sensitivity, accuracy and repeatability of CODcr measurement, widen a linear range of and CODcr measurement, and especially improve technical indexes such as low-range measurement accuracy and the like.

A pressure sensor for sensing a fluid pressure in harsh environments such as the air pressure in a tire, by using a chamber partially defined by a flexible membrane (20), the chamber containing a fluid at a reference pressure, such that the flexible membrane (20) deflects due to pressure differentials between the reference pressure and the fluid pressure; and,

• • associated circuitry for converting the deflection of the flexible membrane (20) into an output signal indicative of the fluid pressure; wherein,
  • the membrane (20) is non-planar (22, 24).

It is possible to extend the linear range of the pressure-deflection response with a non-planar membrane (20). Corrugations, a series of raised annuli (22) or other surface features are an added complexity in the fabrication process but can extend the linear range of the sensor by 1 MPa.

The invention discloses a novel rapid multi-parameter platelet functional analyzer. The novel rapid multi-parameter platelet functional analyzer comprises a multi-hole linked cup, a porous linked cup loading table, a diluting cup, a detection cup, a sample absorption needle, a sample absorption needle moving device, a diluent injector, a sample injector, a valve, an air pump, a waste liquid pump, a detection device, a control device and other main functional components. The invention also discloses a platelet functional analyzing method. The method comprises the following steps: the sample blood with equal quantity is respectively put into each hole of a special multi-hole linked cup; the multi-hole linked up filled with a blood sample is put onto the analyzer disclosed by the invention; the analyzer meters and detects the number and volume of platelets of the blood sample in each hole of the multi-hole linked cup, and finally compares and calculates the number of platelets in the blood sample in a contrast hole with the number of platelets in the blood sample in each other holes, thereby obtaining the aggregation ratio of the blood sample under action of different induced polymerization retarders respectively.

The invention relates to a method for preparing a sandwich type photoelectric chemical sensor for cardiac troponin I and belongs to the technical field of nano functional materials, immunoassay and photoelectrochemistry sensation. According to the method, a carboxylation CdS quantum dot is adopted to sensitize a 001 crystal surface of a nano square piece TiO2, then visible light absorption can beimproved, a composite material TiO2/CdS of which the photoelectric activity is remarkably improved is prepared, by using a layer-by-layer self-assembling method, a cardiac troponin I antibody, bovineserum albumin and cardiac troponin I antigen are assembled on the composite material TiO2/CdS, Ag@Cu2O shell-core nanoparticles are adopted as a second antibody marker, and by virtue of the excellentphotoelectric activity of the TiO2/CdS and specific combination of antigen and antibodies of the cardiac troponin I, super-sensitive detection on the cardiac troponin I can be achieved, and the methodhas great significances for analysis and detection on the cardiac troponin I.

The invention discloses an immunochromatographic test strip for quantitatively detecting a canine C-reactive protein and a preparation method thereof. The test strip is composed of a sample pad, a coating film and a water absorbent paper, which are sequentially lapped and pasted on a bottom plate. The coating film comprises a labeling zone, a detection zone and a quality control zone. The labelingzone is coated with a canine CRP monoclonal antibody labeled with fluorescent latex particles and a goat anti-chicken IgY antibody and the canine CRP monoclonal antibody and the goat anti-chicken IgYantibody are labeled to the same fluorescent latex particle. The detection zone is coated with another canine CRP monoclonal antibody at an epitope different from the epitope where the canine CRP monoclonal antibody is arranged. The canine CRP monoclonal antibody and the goat anti-chicken IgY antibody are connected to the same fluorescent latex. The detection zone and the quality control zone share the same fluorescent latex particle so that the signal amount of the reaction system is magnified and thus the sensitivity and accuracy are greatly improved and the linear range is broadened.

The invention relates to a linear isolating circuit based on optical couplers and a method, wherein the circuit comprises an input and output optical coupler PC1, a first voltage follower, a samplingoptical coupler PC2, a subtracter, a second voltage follower, a feedback optical coupler PC3 and a comparing optical coupler PC4, wherein the input and output optical coupler PC1 is connected with theinput end of the isolating circuit in series; the first voltage follower is used for following the output voltage of the optical coupler PC1; the sampling optical coupler PC2 is used for sampling thepractical input current of a photoreceptor of the optical coupler PC1; the subtracter is used for computing the subtraction of the output voltage of the photoreceptor of the optical coupler PC1 and the cathode voltage of an illuminating device of the optical coupler PC2; the second voltage follower is used for following the output voltage of the subtracter; the feedback optical coupler PC3 is used for feeding the feedback comparing control current of the second voltage follower and the optical coupler PC4 to the input end of the isolating circuit; an illuminating device of the comparing optical coupler PC4 is connected with an illuminating device of the optical coupler PC3 in series; the optical coupler PC1 is matched with the optical coupler PC2; the optical coupler PC3 is matched with the optical coupler PC4 and the current transmission of the optical coupler PC1 is larger than 1. The linear isolating circuit has the advantages of simple structure, high precision, good linear degree, low cost, high safety and the like.

The present invention relates to the technical field of analytical chemistry, and discloses a method for detecting beta-receptor agonist residual quantity in animal derived food, the method is based on a GB / T22286-2008 detection method, and aims at the defects of a long enzymolysis step for sample extraction of the GB / T22286-2008 detection method, a new sample processing step without enzymolysis is provided, detection time and cost are improved significantly, and the method has high accuracy, sensitivity and precision, and is suitable for detection of large quantities of samples.

The invention discloses a method for determining organic volatile substances in soil by using the gas chromatography-mass spectrometry-headspace. The method for determining the organic volatile substances in the soil by using the gas chromatography-mass spectrometry-headspace comprises the following steps of: step 1, soil collection; step 2, sample preservation and preparation; step 3, headspace analysis; step 4, gas chromatography-mass spectrometry analysis; step 5, standard curve establishment; and step 6, calculation. The method for determining the organic volatile substances in the soil byusing the gas chromatography-mass spectrometry-headspace is characterized in that: the soil is collected into a sample bottle, and the sample bottle is sealed; meanwhile, a soil parallel sample is collected and placed in a sample bottle for sealed storage; then the sample bottles are brought back to a laboratory for analysis; the sample bottles are taken out in the laboratory and returned to theroom temperature; 2g of the sample is weighed and placed into a 22mL headspace bottle; 10mL of matrix correction solution is quickly added to the headspace bottle, and then sealed immediately; chromatographically pure methanol is taken into a sample introduction bottle; and then a volatile standard stock solution is taken into methanol. According to the invention, the organic volatile substances in the sample are not easy to volatilize and lose; the operation is convenient; the resolution is high; the linear range is good; the sensitivity is high; and the interference by the impurity peak is small.

The invention relates to a biochip for detecting a myocardial infarction marker, and belongs to the technical field of POCT detection. The biochip comprises biosensors, which are a wafer platform anda spotted antibody coated on the wafer platform, wherein the spotted antibody can form an immune complex with a magnetic bead conjugated antibody and the marker protein, and complex aggregation of magnetic beads will be formed on the biosensor coated with the spotted antibody when the blood sample contains the myocardial infarction marker protein. In the technical solution, the magnetic beads havea large specific surface area, and more antibodies are combined to improve the sensitivity of the detection; at the same time, the biomolecules and proteins are not magnetic, the magnetic beads not bound to the sensor cannot excite the magnetic field to generate magnetic resistance signals, and the specificity is high than the traditional chemiluminescence method. The invention also provides a detection method for applying the biochip, which can realize micro-measurement and micro-detection, and shortens the diagnosis time by controlling the detection time of 15 minutes to 20 minutes.

The invention discloses an electrochemical detection method of cocaine based on rolling circle amplification and a supramolecular aptamer. The method comprises the steps of dropwise adding an aptamer segment Co3S onto a cleaned gold electrode, taking out for sealing after overnighting in a refrigerator, dropwise adding an aptamer segment Co3B and a sample to be detected on the gold electrode, after reaction at 37 DEG C, dropwise adding a streptavidin solution for incubation, then adding a cyclized DNA (deoxyribonucleic acid) solution for incubation, performing rolling circle amplification, adding a detection probe for hybridization and performing DPV (differential pulse voltammetry) signal detection. The method utilizes the rolling circle amplification and the supramolecular aptamer for electrochemical detection of the cocaine for the first time, greatly improves sensitivity and specificity of cocaine detection, and allows a linear detection range to reach 10-500nM. The streptavidin solution and cyclized DNA in the same volume and at the same concentration are utilized, an identification element and an amplifier element are separated, a blank signal is decreased by a bridge connection effect of streptavidin is only utilized, and the sensitivity and the linear range of the detection are greatly improved and extended.